In the present inkjet printing technical field, an inkjet recording system generally comprises a transfer mechanism, a paper feeding mechanism, a control mechanism, a correction mechanism and a cleaning mechanism etc. Through systematical combination and integration, these mechanisms constitute a complete printer, wherein the transfer mechanism comprises a spray nozzle, an ink channel and an ink supply system.
The transfer mechanism is in “on-line” or “off-line” mode. The so-called “on-line” mode means that the printer's ink refilling mechanism, namely, ink cartridge is on a printing head and shuttles together with its moving axis. The ink cartridge of such mode moves together with the printing head. The ink inside the ink cartridge is often vibrated and is prone to form an air-liquid mixture with air. However, in the vibration process, the ink becomes uniform to avoid of deposit.
The “off-line” mode means that the ink cartridge and the printing head are connected via an ink supply pipe, and the ink cartridge fixed inside the ink cartridge chamber, does not move together with the printing head. The ink cartridge of such mode has stable position to avoid of forming an air-liquid mixture, but is apt to deposit.
As to the “off-line” mode, an ink volume detection system usually uses the analog information like chip for the detection. In order to ensure the accuracy of detection, it is provided with the material detection at the same time, namely physical detection of the ink volume information.
The physical detection usually uses light detection method, that is to say, light emitting portion on one end of a printer detection sensor emits the light, while a light receiving portion on the other end receives the light. When the receiving portion can't receive the light, the printer makes prompt that the ink is completely consumed. Therefore, the ink cartridge matching the printer needs a corresponding detection device to block or change the light path. Meanwhile, it must also reflect the true ink volume information.
However said inkjet printer is widely installed with an ink volume optical detection unit comprising a light-emitting portion and a light receiving portion, and the terminals on the ink cartridge that the ink volume inside an ink cartridge is detected through the exchange of electronic signals generated by contacts among terminals on the ink cartridge. However, problem usually occurs due to poor contact caused by the ink adhesion. Therefore, to prevent this problem, it is preferable to use an optical detection unit like an optical sensor.
In addition, it is widely known that the ink cartridge structure be installed on a main body in a irremovable manner. The printer with said structure different from the structure with an ink cartridge on a carriage, the ink cartridge does not move in the printing process, so ink bubble will not appear.
Therefore, a new art is proposed in Patent US20070229616, wherein a light blocking portion with rotable portion function is configured for detecting the residual ink volume This light blocking portion is connected to a hollow floater portion via a movable arm and moves as the residual ink volume changes. Furthermore, when the residual ink volume is insufficient, the light blocking portion departs from a blocking position between the light emitting portion and the light receiving portion. The printer prompts that the ink is consumed. However, this method only serves as a prompt to user when the ink is consumed and can't accurately reflect the residual ink volume.
Therefore in Patent US20090184991, an ink cartridge is invented that can accurately prompt the residual ink amount. As shown in FIG. 1, this ink cartridge also uses a floater and a plurality of light blocking portions and transmitting portions. As the ink level becomes lower, the position of a floating component changes. The blocking portions continuously block the light between the light emitting portion and light receiving portion by several times. A counter will judge the ink volume inside the ink cartridge according to the blocking times.
In theory, said detection method can prompt the ink volume accurately, but the effect is not ideal in the practice, which is mainly caused by that 1. As a mechanism is complicated, many components like connecting arm or encoding board are used to connect the floater to the blocking portions. Due to the influence by a surface tension of the ink, such components are often adhered to a side wall of an ink storage chamber, which leads to inaccurate detection.
2. As the detection mechanism comprises many components like blocking portion, floater, connecting rod and fixing shaft, it imposes high requirement on the cost and technique of the installation and components, which increases the cost and manufacturing difficulty of the ink cartridge in an intangible manner.